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view src/share/vm/prims/jvmtiClassFileReconstituter.hpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
author | tschatzl |
---|---|
date | Fri, 10 Oct 2014 15:51:58 +0200 |
parents | 55fb97c4c58d |
children | 4ca6dc0799b6 |
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/* * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_PRIMS_JVMTICLASSFILERECONSTITUTER_HPP #define SHARE_VM_PRIMS_JVMTICLASSFILERECONSTITUTER_HPP #include "jvmtifiles/jvmtiEnv.hpp" class JvmtiConstantPoolReconstituter : public StackObj { private: int _cpool_size; SymbolHashMap* _symmap; SymbolHashMap* _classmap; constantPoolHandle _cpool; instanceKlassHandle _ikh; jvmtiError _err; protected: instanceKlassHandle ikh() { return _ikh; }; constantPoolHandle cpool() { return _cpool; }; u2 symbol_to_cpool_index(Symbol* sym) { return _symmap->symbol_to_value(sym); } u2 class_symbol_to_cpool_index(Symbol* sym) { return _classmap->symbol_to_value(sym); } public: // Calls to this constructor must be proceeded by a ResourceMark // and a HandleMark JvmtiConstantPoolReconstituter(instanceKlassHandle ikh){ set_error(JVMTI_ERROR_NONE); _ikh = ikh; _cpool = constantPoolHandle(Thread::current(), ikh->constants()); _symmap = new SymbolHashMap(); _classmap = new SymbolHashMap(); _cpool_size = _cpool->hash_entries_to(_symmap, _classmap); if (_cpool_size == 0) { set_error(JVMTI_ERROR_OUT_OF_MEMORY); } else if (_cpool_size < 0) { set_error(JVMTI_ERROR_INTERNAL); } } ~JvmtiConstantPoolReconstituter() { if (_symmap != NULL) { os::free(_symmap, mtClass); _symmap = NULL; } if (_classmap != NULL) { os::free(_classmap, mtClass); _classmap = NULL; } } void set_error(jvmtiError err) { _err = err; } jvmtiError get_error() { return _err; } int cpool_size() { return _cpool_size; } void copy_cpool_bytes(unsigned char *cpool_bytes) { if (cpool_bytes == NULL) { assert(cpool_bytes != NULL, "cpool_bytes pointer must not be NULL"); return; } cpool()->copy_cpool_bytes(cpool_size(), _symmap, cpool_bytes); } }; class JvmtiClassFileReconstituter : public JvmtiConstantPoolReconstituter { private: size_t _buffer_size; u1* _buffer; u1* _buffer_ptr; Thread* _thread; enum { // initial size should be power of two initial_buffer_size = 1024 }; inline Thread* thread() { return _thread; } void write_class_file_format(); void write_field_infos(); void write_method_infos(); void write_method_info(methodHandle method); void write_code_attribute(methodHandle method); void write_exceptions_attribute(ConstMethod* const_method); void write_synthetic_attribute(); void write_class_attributes(); void write_source_file_attribute(); void write_source_debug_extension_attribute(); u2 line_number_table_entries(methodHandle method); void write_line_number_table_attribute(methodHandle method, u2 num_entries); void write_local_variable_table_attribute(methodHandle method, u2 num_entries); void write_local_variable_type_table_attribute(methodHandle method, u2 num_entries); void write_stackmap_table_attribute(methodHandle method, int stackmap_table_len); u2 inner_classes_attribute_length(); void write_inner_classes_attribute(int length); void write_signature_attribute(u2 generic_signaure_index); void write_attribute_name_index(const char* name); void write_annotations_attribute(const char* attr_name, AnnotationArray* annos); void write_bootstrapmethod_attribute(); address writeable_address(size_t size); void write_u1(u1 x); void write_u2(u2 x); void write_u4(u4 x); void write_u8(u8 x); public: // Calls to this constructor must be proceeded by a ResourceMark // and a HandleMark JvmtiClassFileReconstituter(instanceKlassHandle ikh) : JvmtiConstantPoolReconstituter(ikh) { _buffer_size = initial_buffer_size; _buffer = _buffer_ptr = NEW_RESOURCE_ARRAY(u1, _buffer_size); _thread = Thread::current(); write_class_file_format(); }; size_t class_file_size() { return _buffer_ptr - _buffer; } u1* class_file_bytes() { return _buffer; } static void copy_bytecodes(methodHandle method, unsigned char* bytecodes); }; #endif // SHARE_VM_PRIMS_JVMTICLASSFILERECONSTITUTER_HPP